“These dangers further expose the platypus to even worse local extinctions with no capacity to repopulate areas,” lead author Gilad Bino, a researcher at the University of NSW’s Centre for Ecosystem Science, said. Such a trajectory could place the platypus on the “brink of extinction”, he said.
Platypuses, along with four species of echidnas, are the world’s only monotremes. European collectors receiving their first specimens thought their combination of fur, webbed feet and duck bill too alien to be genuine.
Their numbers, along with those many other aquatic species, are likely to have been hammered by the intensifying drought and record heatwave across much of their range – even before the bushfires.
Disruption of Murray Darling and Great Dividing Range habitats means “the consequences are grim for the platypus”, said Richard Kingsford, director of the UNSW centre and another of the study’s authors. “This is impacting their ability to survive during these extended dry periods and increased demand for water.”
Despite platypuses becoming far less common, their decline has barely registered with governments. That’s despite the International Union for Conservation of Nature (IUCN) recently downgrading the conservation status of the nocturnal animal to “near threatened”.
“If we lost the platypus from Australian rivers, you would say, What sort of government policies or care allow that to happen?” Professor Kingsford said. “What sort of nonchalance and disregard for one of the world’s most important species has allowed this to happen?”
Dr Bino said there was “an urgent need for a national risk assessment” for the animal.
A spokesman for Sussan Ley, the federal Environment Minister, said: “Prior to this study, there has not been information collated to suggest that the platypus was threatened so it has not been assessed.”
A spokeswoman for the Victorian Environment Department said: “We’re working with the federal government to determine whether the platypus should be listed as a threatened species at a national level.” She added that Victoria’s own nomination was “still being considered”.
A NSW Environment spokeswoman said the government “recognises that a range of factors, exacerbated by the current prolonged drought conditions, may be placing the long term viability of platypus populations at risk”.
“At this stage, NSW government scientists and ecologists believe the Hunter, New England and Central West areas are of most concern,” she said, adding that work included controlling foxes and relocating platypuses away from drying pools.
The study was the first nationwide attempt to establish a so-called metapopulation model for the platypus.
Researchers collated all available information, including historical records and newspaper clippings, to assess the animal’s extent and numbers.
The report also analysed the frequency of extreme drought, population fragmentation caused by dam development, and the effects of land clearing including bank erosion.
“We are not monitoring what we assume to be a common species,” Dr Bino said. “And then we may wake up and realise it’s too late.”
Catriona Stirrat is an intern journalist at The Sydney Morning Herald.